Electrographic printers use a developer mixing apparatus and related processes for mixing the developer or toner used during the printing process. The four-color electrophographic printers, for example, employ the four color toners, cyan, magenta, yellow and black (CMYK) used in the printing process to form a color image. The term “electrographic printer,” is intended to encompass electrophotographic printers and copiers that employ dry toner developed on an electrophotographic receiver element, as well as ionographic printers and copiers that do not rely upon an electrophotographic receiver
Digital color reproduction printing systems typically include digital front-end processors, digital color printer, and post finishing systems (e.g., UV coating system, glosser system, laminator system, and etc). It reproduces original pleasing color onto substrates (such as paper). The digital front-end processors take input electronic files (such as postscript command files) composed of images from other input devices (e.g., a scanner, a digital camera) together with its own internal other function processors (e.g., raster image processor, image positioning processor, image manipulation processor, color processor, image storage processor, substrate processor, and etc) to rasterizing input electronic file to become proper image bitmaps for printer to print. An operator may be assisted to set up parameters such as layout, font, color, paper, post-finishing, and etc among those digital font-end processors. The printer (e.g., an electrographic printer) takes rasterized bitmap and renders the bitmap into a form that can control the printing process from the exposure device to writing the image onto paper. The post-finishing system puts finishing touch on the prints such as protection, glossing, and binding etc.
In an electrophotographic modular printing machine of known type, for example, the NexPress 2100 printer manufactured by NexPress Solutions, Inc., of Rochester, N.Y., color toner images are made sequentially in a plurality of color imaging modules arranged in tandem, and the toner images are successively electrostatically transferred to a receiver member adhered to a transport web moving through the modules. Commercial machines of this type typically employ intermediate transfer members in the respective modules for the transfer to the receiver member of individual color separation toner images. Of course, in other electrostatographic printers, each color separation toner image is directly transferred to a receiver member.
Electrostatographic printers having multicolor capability are known to also provide an additional toner depositing assembly for depositing clear toner. The provision of a clear toner overcoat to a color print is desirable for providing protection of the print from fingerprints and reducing certain visual artifacts. However, a clear toner overcoat will add cost and may reduce color gamut of the print; thus, it is desirable to provide for operator/user selection to determine whether or not a clear toner overcoat will be applied to the entire print. In U.S. Pat. No. 5,234,783, issued on Aug. 10, 1993, in the name of Yee S. Ng, it is noted that in lieu of providing a uniform layer of clear toner, a layer that varies inversely according to heights of the toner stacks may be used instead as a compromise approach to establishing even toner stack heights. As is known, the respective color toners are deposited one upon the other at respective locations on the receiver member and the height of a respective color toner stack is the sum of the toner contributions of each respective color and provides the print with a more even or uniform gloss.
In U.S. patent application Ser. No. 11/062,972, filed on Feb. 22, 2005, in the names of Yee S. Ng et al., a method is disclosed of forming a print having a multicolor image supported on a receiver member wherein a multicolor toner image is formed on the receiver member by toners of at least three different colors of toner pigments which form various combinations of color at different pixel locations on the receiver member to form the multicolor toner image thereon; forming a clear toner overcoat upon the multicolor toner image, the clear toner overcoat being deposited as an inverse mask; pre-fusing the multicolor toner image and clear toner overcoat to the receiver member to at least tack the toners forming the multicolor toner image and the clear toner overcoat; and subjecting the clear toner overcoat and the multicolor toner image to heat and pressure using a belt fuser to provide an improved color gamut and gloss to the image. The inverse masks, the pre-fusing conditions, and the belt fuser set points can be optimized based on receiver member types to maximize the color gamut. However, due to the significant change in the color gamut, new color profiles will need to be built for each receiver member used to obtain the desired color.
Color shift is quite common in electrophographic printing systems during long printing projects runs. The system environment can change when components, such as the fuser roller, change their operational characteristics over time. Typically linearization processes are used to re-calibrate the printer system to its correct status so that digital front-end processors are more independent from printer behavior change. However, in the whole color reproduction printing system, which includes both printer and post finishing system (e.g., UV coater, glosser, and etc), the linearization process alone cannot fully correct the whole color reproduction system variability. If the resultant colors especially memory sensitive colors were incorrectly shifted (for example, red shift or green shift), they would be poorly perceived and unacceptable. These are important colors that are very visible to customers. It is important to make corrections and adjustments to recreate the desired perceived memory colors. [Ref: A psychophysical study on the influence factors of color preferences in photographic color reproduction; Proceeding of SPIE-IS&T, vol. 5668]
Previously the “tweaking of color” has been performed manually. However, a manual “color tweaking” process is tedious and only addresses some specific colors that customers are very sensitive to when they view their prints. This invention anticipates this problem and can overcome this shortcoming of previous printing systems by weighting the important process-sensitive colors in such a way that includes all important memory sensitive colors in an automated process that takes into account all-important process-sensitive colors and dynamically adjusts the system to the desired parameters.
The present invention overcomes this shortcoming by correcting the imbalances that can occur in printing colors such as process-sensitive colors in a color reproduction printing system. The apparatus and related method describe correcting color with customer adjustable weights among process-sensitive colors desired by individual customers. The following invention solves the current problems with representation of process-sensitive colors, such as memory sensitive colors, neutral colors, black and primary colors in a wide variety of situations.